Australia batsman David Warner has been dropped for the country's Champions Trophy match against New Zealand on Wednesday (June 12), Cricket Australia said, amid England complaints of an "unprovoked physical attack" on one of its players.

Cricket Australia said in an emailed statement that the player had been reported for breaching its code of conduct relating to "unbecoming behaviour".

Warner "was allegedly involved in a physical altercation with an England player in the early hours of Sunday morning following the ICC Champions Trophy match between the teams in Birmingham", CA said.

The England player allegedly involved in the incident was reportedly Joe Root, although this has not been officially confirmed.

The England and Wales Cricket Board (ECB) also said Warner had "initiated an "unprovoked physical attack on a member of the England team in a Birmingham bar following England's 48-run victory over Australia" in the teams' tournament opener at Edgbaston on Saturday.

It added: "Warner has admitted behaving inappropriately and has since apologised to the player involved who has accepted the apology.

"Following a full investigation the England team management has concluded that the England player was in no way responsible for nor retaliated to the attack.

"ECB has concluded that this is a matter for Cricket Australia and have no further comment to make."

Earlier CA said: "Team management have stood down Warner pending the outcome of the hearing, meaning he will miss Australia's match against New Zealand in Birmingham tonight (Wednesday)."

CA said it would not comment further until after the disciplinary hearing.

Warner last month came under fire for a Twitter tirade directed at two respected Australian cricketing journalists after a story about corruption and fixing in the Indian Premier League was illustrated with a picture of him.

After posting a tweet with expletives aimed at journalist Robert Craddock, Warner took issue with Craddock's News Limited colleague Malcolm Conn in abusive tweets that sparked a back-and-forth exchange.

He was found guilty of breaching Cricket Australia's code of behaviour and fined Aus$5,750 (US$5,608).

Cricket Australia says it will not make further comment until after a hearing, a time and date for which have yet to be confirmed.

Glenn Maxwell replaced Warner in the team playing New Zealand, with captain and star batsman Michael Clarke already out of the side because of a recurrence of his longstanding lower back injury.